This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-149208, filed May 22, 2000, the entire contents of which are incorporated herein by reference.
The present invention relates to a single-substrate-processing apparatus for performing a semiconductor process, such as oxidation, diffusion, film formation, or annealing. The term xe2x80x9csemiconductor processxe2x80x9d used herein includes various kinds of processes which are performed to manufacture a semiconductor device or a structure having wiring layers, electrodes, and the like to be connected to a semiconductor device, on a target substrate, such as a semiconductor wafer or an LCD substrate, by forming semiconductor layers, insulating layers, and conductive layers in predetermined patterns on the target substrate.
In the process of manufacturing semiconductor devices, several types of heat-processing apparatuses are used for subjecting target substrates, such as semiconductor wafers, to a semiconductor process, such as oxidation, diffusion, film formation, or annealing. A single-substrate-processing apparatus, which handles wafers one by one, is known as one of these heat-processing apparatuses. The single-substrate-processing apparatus generally includes an airtight process chamber, and a worktable disposed in the process chamber for mounting a target substrate.
As a single-substrate-processing apparatus, there is an oxidizing apparatus using ozone (O3) gas as a process gas. The oxidizing apparatus includes a ceramic worktable in which a resistance heating body is embedded. During a process, ozone gas is supplied as a process gas from above in the process chamber and is irradiated with ultraviolet (UV) rays emitted from UV lamps. With the UV ray irradiation, the ozone is decomposed into oxygen (O2) and oxygen radicals (o+), which are then supplied onto the surface of a wafer.
The worktable of the oxidizing apparatus has an electrically insulating surface. Accordingly, during a process, the wafer and the worktable are charged with static electricity due to ions and electrons generated by the UV ray irradiation. The static electricity causes the wafer to be attracted and held on the worktable by electrostatic force (Coulomb""s force). Consequently, when the wafer is transferred from the worktable after the process, separating the wafer from the worktable requires a large force. If the wafer cannot be separated from the worktable smoothly, the wafer may be damaged.
In order to solve this problem, there is a structure known in which a conductive mount plate is disposed on a worktable, and is grounded through a lead line, so that static electricity is removed. This structure, however, entails problems in that, as additional elements are needed, the structure becomes complicated, maintenance operations become difficult, and the cost increases, due to the arrangement of the conductive mount plate and the lead line.
An object of the present invention is to provide a single-substrate-processing apparatus for a semiconductor process, which removes static electricity generated on a worktable with a simple structure, thus simplifying maintenance operations and not increasing the cost.
According to a first aspect of the present invention, there is provided a single-substrate-processing apparatus for performing a semiconductor process, comprising:
an airtight process chamber;
a worktable configured to support a target substrate within the process chamber, and having an insulating surface;
a supply section configured to supply a process gas into the process chamber;
an exhaust section configured to vacuum-exhaust the process chamber; and
a conduction structure configured to conduct static electricity generated on the worktable to a grounded portion outside the process chamber, the conduction structure having a first conductive film formed on the insulating surface of the worktable.
According to a second aspect of the present invention, there is provided a single-substrate-processing apparatus for performing oxidation of a semiconductor process, comprising:
an airtight process chamber;
a worktable configured to support a target substrate within the process chamber, and having an insulating surface;
a pedestal standing upright in the process chamber, supporting the worktable, and having an insulating surface;
a supply section configured to supply a process gas containing an oxidizing gas into the process chamber;
an exhaust section configured to vacuum-exhaust the process chamber;
a window formed in a casing of the process chamber and facing the worktable;
a UV lamp disposed outside the process chamber and facing the window, the UV lamp being configured to radiate UV rays onto the oxidizing gas above the worktable to activate the oxidizing gas; and
a conduction structure configured to conduct static electricity generated on the worktable to a grounded portion outside the process chamber, the conduction structure having a first conductive film formed on the insulating surface of the worktable, and a second conductive film formed on the insulating surface of the pedestal and electrically connected to the first conductive film.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.